Crystal Engineering: Design of Ternary CocrystalsBased Purely on Halogen Bonding

Abstract

Crystal engineering is the synthesis of crystals with predefined and targeted properties using non-covalent interactions. Halogen bond being one of the interactions is the bond between a halogen atom (Lewis acid) and a neutral or negatively charged Lewis bases. Different components are bought together and crystallized in solid-state to form multicomponent crystals. The importance of halogen bonded cocrystals comes from the ability to control function and structure of solids using the moderate strengths of halogen bonds. To find design strategies for the formation of purely halogen-based ternary cocrystals, some cocrystals formed by 1,4-diiodotetrafluoro benzene withdifferent organic bases characterised using SC-XRD are reported. 4-iodo-1-iodoethynylbenzene pure crystals have been synthesized for the first time and type I and type II of halogen bonds types are noted. 1,4-diiodotetrafluoro benzene and 4-iodo-1-iodoethynylbenzene have been exploited well in the scope of getting a purelyhalogen based ternary cocrystal